fix(app, android): fix TaskExecutor ConcurrentModificationException

packages/app/android/src/main/java/io/invertase/firebase/common/TaskExecutorService.java

@@ -17,11 +17,10 @@
  *
  */
 
-import io.invertase.firebase.common.ReactNativeFirebaseJSON;
-
+import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.List;
 import java.util.Map;
-import java.util.Set;
 import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.concurrent.RejectedExecutionHandler;
@@ -36,7 +35,7 @@ public class TaskExecutorService {
   private final String name;
   private final int maximumPoolSize;
   private final int keepAliveSeconds;
-  private static Map<String, ExecutorService> executors = new HashMap<>();
+  private static final Map<String, ExecutorService> executors = new HashMap<>();
 
   TaskExecutorService(String name) {
     this.name = name;
@@ -73,39 +72,39 @@ public ExecutorService getExecutor(boolean isTransactional, String identifier) {
   }
 
   private ExecutorService getNewExecutor(boolean isTransactional) {
-    if (isTransactional == true) {
+    if (isTransactional) {
       return Executors.newSingleThreadExecutor();
     } else {
-      ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(0, maximumPoolSize, keepAliveSeconds, TimeUnit.SECONDS, new SynchronousQueue<Runnable>());
+      ThreadPoolExecutor threadPoolExecutor = new ThreadPoolExecutor(0, maximumPoolSize, keepAliveSeconds, TimeUnit.SECONDS, new SynchronousQueue<>());
       threadPoolExecutor.setRejectedExecutionHandler(executeInFallback);
       return threadPoolExecutor;
     }
   }
 
-  private RejectedExecutionHandler executeInFallback = new RejectedExecutionHandler() {
-    public void rejectedExecution(Runnable r, ThreadPoolExecutor executor) {
-      if (executor.isShutdown() || executor.isTerminated() || executor.isTerminating()) {
-        return;
-      }
-      ExecutorService fallbackExecutor = getTransactionalExecutor();
-      fallbackExecutor.execute(r);
-    };
+  private final RejectedExecutionHandler executeInFallback = (r, executor) -> {
+    if (executor.isShutdown() || executor.isTerminated() || executor.isTerminating()) {
+      return;
+    }
+    ExecutorService fallbackExecutor = getTransactionalExecutor();
+    fallbackExecutor.execute(r);
   };
 
   public String getExecutorName(boolean isTransactional, String identifier) {
-    if (isTransactional == true) {
+    if (isTransactional) {
       return name + "TransactionalExecutor" + identifier;
     }
     return name + "Executor" + identifier;
   }
 
   public void shutdown() {
-    Set<String> existingExecutorNames = executors.keySet();
-    for (String executorName : existingExecutorNames) {
-      if (executorName.startsWith(name) == false) {
-        existingExecutorNames.remove(executorName);
-      } else {
-        removeExecutor(executorName);  
+    synchronized(executors) {
+      List<String> existingExecutorNames = new ArrayList<>(executors.keySet());
+      for (String executorName : existingExecutorNames) {
+        if (!executorName.startsWith(name)) {
+          executors.remove(executorName);
+        } else {
+          removeExecutor(executorName);
+        }
       }
     }
   }

packages/app/e2e/config.e2e.js

@@ -26,7 +26,7 @@ describe('config', function () {
   });
 
   describe('json', function () {
-    xit('should read firebase.json data', async function () {
+    it('should read firebase.json data', async function () {
       const jsonData = await NativeModules.RNFBAppModule.jsonGetAll();
       jsonData.rnfirebase_json_testing_string.should.equal('abc');
       jsonData.rnfirebase_json_testing_boolean_false.should.equal(false);

tests/app.js

@@ -53,14 +53,17 @@ function Root() {
       style={{ flex: 1, paddingTop: 20, justifyContent: 'center', alignItems: 'center' }}
     >
       <Text style={{ fontSize: 25, marginBottom: 30 }}>React Native Firebase</Text>
-      <Text style={{ fontSize: 25, marginBottom: 30 }}>End-to-End Testing App2</Text>
+      <Text style={{ fontSize: 25, marginBottom: 30 }}>End-to-End Testing App</Text>
       <Button
+        style={{ flex: 1, marginTop: 20 }}
         title={'Test Native Crash Now.'}
         onPress={() => {
           firebase.crashlytics().crash();
         }}
       />
+      <View testId="spacer" style={{ height: 20 }} />
       <Button
+        style={{ flex: 1, marginTop: 20 }}
         title={'Test Javascript Crash Now.'}
         onPress={() => {
           undefinedVariable.notAFunction();